How to get past canned interview responses

Some interviewees show up so well prepared that, to get unrehearsed answers, hiring managers have to ask fewer predictable questions to get past canned interview responses.

FORTUNE – Dear Annie: Your recent column on “elevator pitches” really hit home with me because I’m hearing a lot of them lately. I’m trying to hire someone to replace a great employee who suddenly quit and, so far, I’ve interviewed five people. They’re all technically qualified with the right kind of experience, and HR is sending me a couple more. The problem is this: I keep hearing the same, or very similar, answers over and over again.

Maybe it’s just me, since I haven’t had much experience or formal training in hiring, but it seems the people I’ve met have rehearsed for the interviews ahead of time so thoroughly that it’s hard to get past their canned responses. So how do I make an intelligent decision about which one would be best for this job? Any advice? – Snowed in Chicago

Dear Snowed: First, it’s not just you. Not only have many job candidates these days carefully practiced their answers to the queries interviewers usually pose, but “some candidates, especially for management roles, even have professional interview coaches advising them on what to say and how to say it,” observes Patrick Sweeney, president of human resources consulting firm Caliper. “So it’s difficult for any interviewer to penetrate the façade.”

What’s more, it’s common knowledge by now that some people score higher on standardized tests than others because they’re simply better test-takers, and Sweeney notes that the same is true of job interviews. “It’s not unusual to get dazzled by someone who has a high energy level, who brings lots of excitement to an interview and has all the ‘right’ answers,” he says. “Some people thrive on making that great first impression.”

So how do you avoid getting snowed? Sweeney is co-author (with Caliper founder and CEO Herb Greenberg) of a book called How to Hire & Develop Your Next Top Performer that you might want to check out. It’s aimed primarily at managers of sales teams, but spells out a hiring method that could work for anybody — including how to come up with interview questions that are impossible to prepare for in advance.

The first step: Think hard about the position you’re hiring for, and make a list of exactly what traits it calls for. You’ve mentioned that all your candidates so far have good technical skills and solid experience, but look beyond those. “Once you have your list, you can look at each candidate through that lens,” Sweeney says.

For a sales position, for instance, you want someone with a lot of resilience, who can bounce back quickly from rejection. So something like, “After getting turned down by customers several times, what’s the hardest part, for you, of making that next sales call?” Sweeney says that a question like that “can give you a real window into how the person responds to a specific situation.”

Tom Gartner, president for North America of rental-car giant Avis Budget Group (CAR), took this approach one step further. He had all the proven top performers in the company take an in-depth personality assessment, and drew a list of traits from the results. “Insights into what all the top employees have in common in essence created a blueprint,” Sweeney says. “Hiring managers can assume that people with those traits will excel at the company.”

Your own list for this particular job could serve as the basis for coming up with “questions people can’t answer with a rehearsed speech,” he adds. His personal favorite: “Tell me your least favorite part of the job you have now, the part you’d get rid of if you could.” Says Sweeney, “If the candidate replies with something that calls for one of the traits on your list, then you’ve just found out all you need to know.”

An important caveat: Most hiring managers (including, probably, you) are swamped with other duties, so they take two shortcuts that can be hazardous. One is looking for a candidate who most closely matches the person he or she would be replacing.

“If you’ve made a list of, let’s say, five qualities you’re looking for, the employee who just quit probably really only had three or four of them,” Sweeney says. Not only that, but the job description dating back to when that person was hired is unreliable: “The job itself probably morphed to fit him or her over time, and your company and industry may have changed a lot too, so the old job description is no longer accurate.” By sticking to a list of attributes you really need now, he says, you’re more likely to focus on the right things, and weed out the pat elevator pitch responses.

Busy managers also rely too heavily on experience. “You want to hire someone who can grow and change with the company over time,” he says. “Experience is … easy to be dazzled by. But it’s often not a good indicator of what someone can do.”

A person might have been selling ads for a TV network for a long time, for instance, “but someone who’s never sold anything but understands social media may do better” in the future, he says. “It’s often better to find potential than experience.” In other words, if your industry is going through any kind of upheaval — and these days, what business isn’t? — adaptability may be one of the traits you need most.